Heat interchanger



Nov. 24, 1936. R. H. SWART HEAT ImElmH.L\NGERA FiledMay l5, 1955 arts but will be particularly described in connecl Patented Nov. 24, 1936 HEAT INTERCHAN GER Richard H. Swart, Beloit, Wis., assignor to General Refrigeration Corporation, Beloit, Wis., a corporation of Delaware Application May 13, 1935, Serial No. 21,172

3 Claims.

The invention relates to improvements in heat interchangers for use in refrigerating systems and has more particular reference to apparatus for reducing the heat content of the liquid refrigerant by bringing the same into heat exchanging relation with the cooled evaporated refrigerant v being returned to the compressor.

The invention Will be found useful in numerous tion with a refrigerating system operating onthe compression expansion cycle. To condense the high temperature refrigerant gas leaving the compressor to change the same to its liquid statethe gas is subjected to a; cooling medium such as water which flows in a direction counter to that of the gas. The present invention has for its object the provision of apparatus for further lowering the temperature of the liquid refrigerant in advance of delivering the same to the expansion valve by subjecting the liquid refrigerant to the cool evaporated gas withdrawn from the evaporating coils.

Another object of the invention is to provide a heat interchanger for the purposes described that will operate at a high thermal emciency.

Another object resides in the provision of a.

, heat interchanger having a plurality of small tubes for conducting the liquid refrigerant into heat exchanging relation with the cool evaporated refrigerant, thereby increasing the available surface for contact with the cooling medium to secure a more rapid heat transfer.

Another object is to provide a heat interchange having one or more tubes in the form of a spiral or coil for conducting a medium into heat exchanging relation with the medium owi'ng through the heat interchanger and wherein means are positioned Within the coil for directing the medium outwardly into contact with the tubing of the coil.

With these and other objects in View, the invention may Yconsist of certain novel features of construction and operation as will be more fully described and particularly pointed out in the specification, drawing and claims appended hereto.

In the. drawing which illustrates an embodiment of the device and wherein like reference characters are used to designate like parts-.-

Figure l is a longitudinal sectional view on the line I-I of Figure 2 showing a heat interchanger having coiled multiple tubes in accordance with the invention;

Figure 2 is a sectional View taken on line 2-2 of Figure 1;

Figure 2A is a sectional View on line 2A2A of Figure 1;

Figure 3 is a longitudinal sectional view show ing a modification of the invention; and

Figure 4 is a sectional view taken substantially' 5 along line 4-4 of Figure 3.

Referring to Figure 1 of the drawing, the heat interchanger selected for illustration consists of y a drum I0 providing a cylindricalhousing having a plurality ofsmall tubes I I which are coiled into 10 al spiral shape within the housing and extend from end to end thereof. Said housing is closed at its ends by members I2 and I3, each member having a leak-proof joint With the drum and being provided with spaced openings, the larger opening receiving conduits I4 and I5, respectively, and the smaller openings permitting exit of the tubes Il. Connections I6 and I1 are fitted to the respective ends of the multiple tubes I'I, joining the ends of said tubes. 20

The conduits It and l5 may comprise the suction line of a refrigerating system, conduit It connecting the heat interchanger with the evaporator of the system and delivering the evaporated refrigerant discharged by the evaporator 25 to the interior of the drum. I0. Conduit I5 is therefore a continuation of the suction line and conducts the refrigerantA gas. to the compressor of the system. In a like manner the liquid refrigerant' is delivered to the tubes II by the supply line I8 which joins with'connection It, which connection functions to distribute the liquid refrigerant to the multiple tubes. The connection il joins with a pipe 20 forming a continuation of the liquid supply line and conducts the liquid refrigerant discharged from the multiple tubes to the expansion valveof the refrigerating system. l In the operation of the above type of heat interchanger the liquid refrigerant flowing through 40 the multiple tubes is brought into heat exchanging relation with the cool evaporated refrigerant owing through the drum Il).` vAs a result the heat content of the liquid refrigerant is reduced and the same is therefore delivered to the 45 expansion valve of the system at a much lower temperature than would otherwise be the case. The heat is taken up by the refrigerant gas, its

temperature being correspondingly raised and although the transfer of heat from the liquid refrigerant to the cool refrigerant gas does not represent-a gain in energy, there is however a conservation of energy that is reflected by a gain in the efficiency of the refrigerating apparatus.

'Ihe form of heat interchanger shown in Fig- 55 through the heat interchanger.

ure 3 also consists of a drum 30 providing a housing of 4cylindrical shape but in this modification of the invention the drum receives allength of coiled tubing formed from a single tube 3l. The connections I6 and I1 as described with respect to Figure 1 are omitted in this modification since Y the coil is formed of a single tube and as shown in the drawing the liquid refrigerant is delivcred at the right hand end, ows through the coil within the drum, and is discharged at the left hand end. The housing is closed at each end by members 32 and 33, each member having a leak-proof joint with the drum and being provided with spaced openings for permitting passage of the tubing 3| and the conduits 34 and 35, respectively. As previously described the cooling medium which may comprise the evaporated refrigerant is delivered to the drum 30 through conduit 34 and is discharged through conduit 35. For the purpose of removing the dirt particles from the refrigerant gas it is proposed to pack the drum 3U with copper wool designated by numeral 36 which substantially lls the space within the drum except for that taken up by the coiled tubing 3l. The dirt particles will adhere to the copper wool and will in this manner be separated from the stream ofrefrigerant gas passing through the drum. For further ltering of the gas the conduit 35 is provided with an enlarged end 31 located within the drum, which is closed by a screen 38. Fine particles of dirt will adhere to the screen 38 with the result that the gas delivered by conduit 35'to the compressor of the refrigerating system will .have been thoroughly cleaned.

The multiple tubes in the heat interchanger of Figure 1 and the single tube employed in the structure of Figure 3 are coiled in order to materially increase the length of the tubing located within the drum of the heat interchanger. This increase in the length of the tubing increases the surface for contact with the cooling medium and thus results in a more complete transfer of heat and a high thermal efciency for the heat interchanger. This also accounts for the use of the multiple tubes in the device of Figure L` which tubes break up the liquid refrigerant delivered by supply line I8 into a plurality of smaller streams, thus increasing the available surface subjected to contact with the cooling medium..

The multiple tubes also have the effect of increasing the cross sectional area of the passage conducting liquid refrigerant, causing a reduction in velocity of flow of the refrigerant gas Thus, the liquid refrigerant which holds considerable heat when it enters the multiple tubes at the connection IE, is subjected to the cooling action of the evap orated refrigerant for an increased length of time and'is more nearly brought to the temperature of the cooling medium. A vane I9, bent into the form of a helix, extends longitudinally within the coil of tubing in both heat interchangers as shown in Figures 1 and 3, for causing the refrigerant gas flowing through the tubing to travel outwardly where it is caused to contact said tubing. This makes for a more uniform distribution and flow of the cooling medium through the drum of the heat interchanger. Also it will be appreciated that both heat interchangers could be packed withV copper wool in order to secure the highest possible degree of cleanliness in the refrigerant gas leaving the heat interchanger. The use of copper wool has not been shown in connection with the drum l0 of the heat interchanger of Figure 1 and also the screen, such as 38, Figure 3, has been omitted from the suction conduit I5, Figure 1, in order to indicate that these elements are optional and that they may be used in heat interchangers of the invention or may be omitted without affecting their basic principle of operation.

Better thermal eiciency of the apparatus of the invention is secured when the coolingmedium flows through the heat interchanger in a direc-` tion counter to the flow of the liquid refrigerant. Therefore, in the apparatus of Figures 1 and 3 the liquid refrigerant is admitted at one end while the cooling medium is admitted at the opposite end. In operation the liquid' refrigerant as it enters the heat interchanger is subjectedto a cooling medium which is at its highest temperature and which is about to be delivered to conduit l5, while the liquid refrigerant about to leave the heat interchanger is subjected to the cooling medium at its lowest temperature.

What is claimed is:

1. A heat interchanger including a cylindrical shell having end members provided with an inlet and outlet respectively permitting a medium to flow through the shell, a coil comprising a length of continuous tubing positioned within the shell and having the ends of said tubing extending through openings in the end members respectively, a single'supply line connecting With the tubing at one end thereof and a single discharge line connecting with the tubing at the opposite end thereof, and a spiral member positioned within the coil for directing the medium outwardly Where it will contact the tubing of sala coil.

2. A heatfinterchanger including a cylindrical shell having end members provided with an inlet and outlet respectively permitting a medium to flow through the shell, a coil formed of a plurality of tubes positioned within the shell and having the ends thereof extending through openings in the endvmembers respectively, a single supply line connecting with the tubes at one end thereof, the cros's sectional `area of the supply y line being less than the combined cross sectional area of the tubes, and a filtering medium occupying the space surrounding the coil for cleaning the medium flowing through the shell.

3. A heat interchanger including a cylindrical shell having end members provided with an inlet and outlet respectively permitting a medium to flow through the shell, a coil formed of a plurality of tubes 'positioned Within the shell and having the ends thereof extending through open ings in the end members respectively, a single supply line lconnecting with the tubes at one end thereof, the cross sectional area of the supply line being less than the combined cross sectional area of the tubes, a spiral member positioned within the coil for causing the medium flowing 'through the coil to travel outwardly where it will contact said tubes, and a ltering material occupying the space surrounding the coil for cleaning the medium.

RICHARD H. SWART. 

